Absolutely horrible service from Birkenstock

So I've bought a pair of Boston black super grip on the 24th of October 2020 and within 4 months of owning the shoes the cork was falling out of the sole. I then took the pair back to the Somerset west store and was told they would send it to head office to see what could be done. After 4 weeks I had to call the store to find out what was going on to be told that it was normal ware and tear and they would sell me a cork sealer to prevent the problem but they don't have any in stock and that's why they hadn't gotten back to me. I said after paying R2200 for a pair of shoes for the cork to be falling out after 4 months is not normal that they would then check what they could do. After another 2 weeks I had to give them a call again to find out what was going on to then only be told that they were sending the shoes to head office to my confusion because I was told the first time they were sent? the lady on the phone then told me that she doesn't know who told me there were sending the shoes as they only send pictures. Today after now not having the shoes for sometime phoned their head office to find out for myself what's going on to be told the person that deals with damages is not in today? I mean come on every time I have phoned the store the manager hasn't been there and now the damages person is not there. Get your customer service together Birkenstock. I have been a chef for the past 8 years I have worked with chefs that have owned these shoes for 4 years plus and never had this problem.