sim card expired/deactivated..

Since friday ***5 at 5.38pm i have been experiencing problems with my browser and social media (whatsapp, facebook). i have spoken to numerous call centre agents (portia, bianca, riaan, lebogang and jessie) yet this matter was still not resolved. i was told to re-boot my phone, was smsed with directions to do a host routing table and was told that it was going to work. after struggling the entire weekend today i was told that my sim card has expired i will have to do a sim swap. <br> <br> how does a simcard expire and why now? if so why am i still getting phone calls and sms on this \OLD EXPIRED"sim card?<br> <br> this is extremely frustrating as i have business to conduct and cannot do so without my phone working to its full potential."""