Dear Sarah, it is very strange you found the flat cold because I have personally checked all heaters and air conditioning and they heated the house quickly. The hot water runs with a direct propane water heater (no boiler needed) and works perfectly (checked yesterday), so I cannot figure out how it only lasted for two showers. If you had any problem or did not know how to run them properly, I would have appreciated a call or message from you during your stay. About the mattress, the only possible reason is that one bed is slightly harder than the others and that might be an issue for some people who are not used to this kind of surface. I'll change this one by a another soft mattress asap. In any case, all mattresses are brand new and in good condition, so there ARE NOT loose springs at all. We haven't got reported any issue at this respect from any other guest before.
I have to let you know, but I am sure you must be aware of this, you left my flat in an unusually dirty and poor condition that I haven't experienced before from any guest. All the sheets, duvets and covers have been thrown away after your visit. Yours has been my WORST EXPERIENCE with a guest so far and I didn't expect these fallacious comments from you in retaliation.