AN ERROR SIMCARD.....DISGUISTED

My dad updated his rain network to a 5G network 3 weeks ago. He was sent everything via courier but the sim card shows it was not registered. They further deducted money from his account but he doesnt have data. For the last three weeks he has been calling rain and every time the help service tells him that the matter has been escalated to their billing department but nothing has been happening. He now works from home but for the past three weeks he hasnt been able to work because the sim card has an error. They can see its an error from their side but nothing is been done to help him instead each consultant just says the only thing they can do is escalate the matter. We want a working sim card plus pro-rata for the time he was unable to use the data or otherwise give us our money back. it feels like since rain is popular, they are taking people for granted