Worst service i have experience in over a decade

I ordered a 5G SIM and Router and they delivered it on 23rd July. The SIM was faulty. They promised to contact me within 3 biz days to replace the SIM. It is one week later and I am yet to hear from them. It is the ****piest service I have received in a decade. Worse than a dubious used car mechanic. Moreover they expect you to do self support. They have no call centre # on their website and navigating self support is more challenging that getting out of a maze in London. In the future, HelloPeter please include a 0 star rating. 1 star is too kind for service levels such as this. I just need to cancel the damn service. My contacts is Josphat Kinyua *** ref 19436