Laundrette's tumble dryer burned my washing

I used my local laundrette the other day to dry a load of sheets. This is something I do regularly - wash at home, and if the weather isn't playing ball, go to the laundrette to do the drying.

I put the same sized load in as I usually do, and the same number of coins for the machine. However, when the cycle finished and I opened the door, there was a faint smell of burning and the sheets were too hot to touch by hand. When I'd managed to pull them from the machine, it was clear that they had singed to the point that they had discoloured.

I called who I thought was the owner of the laundrette, and they visited to look at the affected machine and my damaged sheets, but told me that they weren't actually the owner, and were only authorised to give compensation of £30 towards the damage.

I told the owner's proxy that this wouldn't be acceptable because to replace the sheets as new (they are very nearly new as it is) would cost close to £150, and his response was that the owner would say that I shouldn't have put more than one coin in the machine at a time, and that he would look at the CCTV to see how long the sheets had been in for.

My response was that a) the need to not put more than one coin it at a time should be listed on signs if it's important, b) the length of the cycle shouldn't affect the temperature of the machine, and on with cottons in on a cotton setting, even a prolonged cycle shouldn't cause burning, and c) the fact that 5 out of 10 machines in the place always seem to have "out of order" signs on them show that the owner needs to replace his machines or maintain them better.

On that last point I was told that, when the guy I was talking to had last mentioned this to the owner, he'd told him that "new machines are expensive". This set alarm bells ringing that this person might not be a model business owner, so I'm fully expecting to have to fight to get my damages covered.

Assuming that I do have to fight, what are my rights and how should I approach things? I know that if it comes to it I can take the small claims court approach, but is this worthwhile for such a small amount? From what I can tell I'd need to pay £25 + 5% upfront, and perhaps more if a court hearing is needed. I'd really rather it didn't have to go this far, so do I have options short of that fairly drastic step?