After service utterly bad

I've been sold a dud! Absolutely horrible experience and through my pregnancy and now with a newborn. Bought a Magnite new off the floor, not even a few months later then the drivers window gives me issues, pausing halfway and just going down, or not moving at all. The cars been for its first service and back to the workshop four times after already and this issue is still not resolved. Had the service person tell me and my husband that all it needs is Q20. As if! Where have you ever heard of a new car window needing to be oiled! They still can't tell me how this will be fixed and I am beyond frustrated. Who has time to keep going back and forth with a new baby!