Incompetent technicians and poor quality

Took my Jeep Compass for an oil change service to MASTER MAC on 13/12/2019 and their incompetent technicians put a lock-tight and threadlock (using a spanner) way beyond its threshold and now no other workshop can service my car without drilling the oil sump out. Phoned them to rectify their mistake and they told me that it is not their responsibility. I advise car owners to steer clear off these scammers.