Billing

I had service and have worked for the company in the past.  I cancelled on May 21 went with AT&T at that time I did not make a payment for that month as I had a piece of equipment to return.  I returned it at the store on June 18 store #1134 the CSR had me pay my last bill then.  I asked him if that was it he said yes.  I just received a bill for $210.17.  I decided to pay the 98.74 monthly charge I still DO NOT BELIEVE I OWE IT.   These deceptive charges they seem to find is unbelievable.  I will tell anyone who will listen about this and plan too!  Something needs to be done does this sound right to you???