Some of vodacoms people doesn’t understand english

Pathetic service from vodacom, I pay R2800.00 every month for my vodacom contrcat and vodacom cannot assist me with a sim issue. For 3 weeks now I am battling with sim issue where I cannot receive any calls on my vodacom contract sim. The bunch of people working there finds it very hard to understand simple english. I informed them we are 5 people in my household and we have a total of 9 cellphones, 3 of them being vodacom contracts and 6 being vodacom prepaid. I told these people several times in English that I took “sim X” (the faulty sim) out of my device and I tested it in all the other devices and “sim X” still gives the same fault. Than I took 8 other sims and tested them in my cellphone and all 8 sims worked in my cell phone.(is this so hard so understand?) the first person tells me 3 weeks ago that I should put my network to manual and then move it to 3G and 4G as I needed the different networks, this was a total inconvenience but I have being doing that so I could use “sim X “ 3- 6 times per day. The fault persisted and then vodacom said I should reset my network settings. Which I did. It still didnt help. Than I was told to do a sim swop. It still didnt fix the problem. Now they say my phone is faulty. But from the beginning I told them all the other sim cards are working in my phone. Now for 2 days vodacom keeps telling me the escalating the matter.