Firstshop seemingly unwilling to uphold warranty

I recently had a NAS failure that I purchased at FirstShop and was still under warranty. At first I was highly impressed with the efficiency and understanding they showed towards picking my unit up and sending it for repairs.

However, after about 3 weeks of not returning my unit, I started getting worried and frustrated. After complaints they said they will give me a new unit but is out of stock. They have now been trying to sell me different brand names (my hard drives won't on) and is consulting for an alternative replacement. They do not seem interested in ordering the same model replacement unit.

I have now lost trust in them and is afraid this matter won't be resolved and I will suffer the financial and data loss due to their inability or unwillingness to either repair or replace my unit.

I will not purchase anything from First Shop anymore and won't definitely not invest in expensive tech as I am suffering financial losses due to weeks of waiting.