BEKO Fridge/Freezer Would transporting cause compressor overheating & Bubbl?

My wife recently bought a Fridge/Freezer off e-bay (please don't laugh). When we got it home we let it stand for 24 hours,then plugged it in checking it periodically over the next 24 hours.While it did cool down a little, not enough to stop a pack of butter from thawing in the fridge. The same with the freezer & a packet of sausages. We found the compressor overheating & heard a bubbling noise, which a friend & other forums & websites told us indicate a lack of refridgerent. Needless to say we are in a dispute & are trying to get our money back.
We have been accused of damaging the Fridge/Freezer during transit, which we refute. It was transported on its side, granted. But in accordance with manufacturers guidelines. It was padded and secured with cargo straps. There was no movement during transit. Could or would this cause the aforementioned symptoms.
Any help on this would be greatly appreciated.
Regards