Replacement of faulty chair

In April 2015 I bought a Regent Mid Back chair. I was concerned that the mechanism that adjusts the height was of good quality, and was assured that it was. Barely 5 months later, in September, the chair began to sink, to the point where it was unusable unless far too low.<br> <br> I took it in to be repaired, and they did - but they told me it would take 21 days. 3 weeks without a chair? I had the mid back chair because of back problems, and until it was ready I was forced to suffer back ache. I got it back, and now, less than 2 months later, the whole thing packed up again and I've had to take it back. This time it failed so badly you can't sit on it at all.<br> <br> They told me I can't get a replacement until it's been repaired twice unsuccessfully. This is completely unacceptable - it means for 6 weeks from the time I first bought the chair I haven't been able to use it, and the one I use in the meantime causes me backache. I live some distance from Makro, and to be constantly loading it up and taking it in is not something I want to be forced to do.<br> <br> As far as I am concerned it should be replaced now - I should not have to suffer because of the poor quality of this item.