I have an Apple iPad 3 32 GB Wifi White A1416 MD329LL?A Serial # DPM J5XVADVD2 that I purchased in 2013. I have used it since that time. I changed providers internet from provider AT&T to Spectrum February 11. When I turned on my I Pad I was prompted to enter my Apple ID and password. There was also a prompt that at some time I had used find my I Phone. After multiple attempts to try and identify my original ID and password, I have been totally locked out and was directed to contact suppor.apple.com/kb/TS4515. What do I do!!!