Old or new lease...are both enforcable???

I was working for a Management Co that offered a 50% discount of the market price of an apartment unit if you live on one of their managed property on 4/9/05. The lease signed was on for 7 months and 11 days or for the duration of 5/21/05-12/31/05. My fiancee and I signed a lease and an addendum which stipulates resident pays utilities such as electic, gas, cable, telephone and is responsible to set those utilities up themselves; but water, sewage and garbage would be set up by the Mangagement Co. As an employee the rent amount was $460.00 mo. I along also signed an employee contract which states I would pay utilities if applicable.
On 9/6/2005 is I was informned that my position will be terminated on 9/21/05 and to stay in the same apartment I would have to sign a lease as a non employee and my new rent amount would be $760.00 mo. On 10/01/05 I paid the new rent amount and on 11/1/05 my new husband and I signed a 6 month good thru 4/30/06. We did not sign sign anything but a new lease. NO ADDENDEUM referring to utilities of water sewage , garbage were signed.
On 10/6/2005 my fiancee and I were married. The new lease was signed on 11/1/05 was listed under my married name and my fiancee is listed as an occupant and the old lease is in my maiden name and was terminated on 9/21/05. The old lease was signed under my maiden name, the employment addendeum and the utility addendum was terminated early on 9/21/05 but was due to expire on 12/31/05. My employment termination expired them and thus a new 6 month lease was signed effective 11/1/05 thru 4/30/06.
On 1/15/05. I received by us mail a water bill from NW&P (a national water company) for new services billing dates 11/27/05-12/26/05, due 2/1/06 for $42.29 (which includes a new account fee of $10.00). This bill was billed to my maiden name (which is not on my new lease). I contacted the management office and advised the District Manager that this must be a mistake as we have never received a water, sewage, garbage bill like this before and that I'm certainly not going to pay it now; I thought the rent increase for $460 to $760 included payment of water, sewage and garbage. I advised them that they should have charged this in 5/05 0r 6/05 so that I would be better prepared and I am still unemployed to this date. The old lease and employment contract has expired as of 9/21/05 a new lease was signed on 11/1/05.The new lease does not have an addendeum stipulating I am responsibles for these utilities.
The District Manager advised me that her office will contact NW&P, the water company and have them adjust the charges all the way back to 5/21/05 and that I will be responsible for payments thru 4/30/06. They advised me that my old employee agreement and Old Lease and my new Residental Lease (non employment) is binding. That I would have to pay and they will bill me.
Now keep in mind this particular apartment community uses metered/allocation based on use(# of persons in the household and size of apartment).

My questions are:
1. Can they make use pay for utilities that were not billed until after termination of old lease? ( as an employee with signed lease and addendum for utilities)
2. Am I obligated to pay for utilities under the new lease with different name, no utilities addendeum and no speacial stipulations on new leasefor utility payment for resident?
3. Can a lease be enforced after it is expired? Addendeums, employment agreements after employment linked to lease?
4. Can a management company have a resident billed by a utility company after a lease expires or terminated without a new addendum?
5. Can a management company have a utility company charge a resident utilities with a lease and no addendeum; specifically when the new lease has no special stipulations and there has been a name change on the new lease and bill in old lease name (maiden name)?