Misleading and does not know what their systems are doing

After a year of having a contract with this company, i lost my sim and did a sim swop. To my surprised, and having to wait the full 24 hours for activation, i insert my sim and it says not registered. I call the company and they advise me that this same number that they gave me on contract is now a prepaid sim. What have i been paying all these months for? Where is my data? Even the company was surprised at this sim being prepaid but no one from management would call to apologise and fix.