RTUI did NOT follow through with advertising for two weeks or more that we paid for! Houston Texas

RTUI did not follow through with their end of the contract that they promised.  After keeping an eye on the register receipts at the store that our advertisment was on we noticed that they suddenly stopped being on the backs of the receipts.  This went on for at least two weeks.  I contacted the supermarket and they conformed that they have not had the ads on the back of their receipts for two or three weeks!  I spoke with the sales representative regarding this issue and he did apologize, but after I told him that we no longer wanted to do business with them because of the screw up, he said it is a non cancellable contract and I reiterated that the contract was broken when they didn't provide the store with our ads.  Again, the contract came up.  Blah, blah, blah!!  This has nothing to do with why we want to cancel with them, but it brought in only 4-6 customers with coupons and they were existing clients!!  No new clients!!  The whole point of having the ad in the first place.  I was then told that I had to approve the next ad and I told them in writing I did not want the ad to run, but they insisted and rather than have the same useless ad run I was forced to make changes to the ad.  I do not like being forced into doing something I don't want to do if I was wronged.  This company must be stopped.