Disappointing Pringles

Towards end of August to early September I purchased a Pringles Sour cream and Thai style chilli. The chips no flavour not even salt. I messaged Pringles right away. They apologized etc and then stated I should contact my nearest post office in two weeks to collect something which makes it my problem in terms of contacting the post office and collecting etc. That's one problem when I try to contact them via Facebook they just read the message and don't reply which is really pathetic. I will never purchase Pringles again