GCS Car Sales in Thrapston, Kettering

Bought a BMW 645ci from this company last month. After completing HPI check found that the dealer still had outstanding finance on the car (without telling me) so had a nervous couple of weeks before they paid it off.
Then after two weeks I got an engine fault warning. On having diagnostic check from BMW specialist and appraisal, faults were found which cost me over one grand to get repaired. These faults surely must have been known by the dealer at time of sale.
GCS were uncooperative and did not honour warranty or request for compensation for repair costs which I am entitled to by law within one month of purchase under the consumer rights act. This is regardless of whether the dealer has inspected the car or not. I wouldn't have trusted GCS to perform inspection and repairs adequately themselves anyway since it already appears they have hidden faults from me.
An unfair, money orientated company with poor customer service.