house renovation gone wrong.

we acquired the services of an architect/contractor for our house renovation. It has been 8 months after the supposed turnover date and still the renovations are not complete even if the architect/contractor has been paid in full with only the retention fee which is to be paid a month after the turnover is remaining. After calling his attention to correct mistakes done in the construction, he started mentioning that there were parts in the house that were renovated that were not included in the contract and is now demanding that we pay for it. he is charging 1/3 of the contract price for those supposed minor renovations and is threatening to seek legal advise. what are we supposed to do. thanks

Did they inform you that they are performing something out of contract and that you will need to pay for it? if not, it is not your fault as the contract is there as guide to what you paid for and what they should be doing.