PC Equipment Repair not done right

Hi. I had a piece of computer hardware repaired the other day. They repaired the thing that was broken. To do so they had to dis-assemble some of it. But they did not re-assemble it correctly, and now something else does not work correctly, and it is also means it is likely to get damaged in the normal course of usage.

They quoted me a price. They also offer pickup & dropoff at an additional cost. I went for this. When I rang them to tell them they'd need to pick it up again as the job was not done properly they told me that the same pickup/dropoff charge would apply again. They said that "the warranty is return to base" or something like that. There was no warranty / paperwork etc. Any thoughts on where I stand would be appreciated, its awful after sales service, but is it legal to do this?

I even told them there's no hurry, pick it up when you have someone in the area, but they said no.

Thanks in advance for any replies...