I have a large cpp overpayment and it is a glitch in the system. I need to get into my turbotax online and can't. How do I do this. Please let me know. Thanks

I have to prove to Canada Revenue Agency that it was a glitch in the system in the Canadian software turbo tax online which was free that showed a large amount in the cpp overpayment section of my income tax return but it was not me who put it in but the system.