EBAY otp

[mcbig43]

Hello I've been charged 19,99 from Ebay 

and I did not purchase anything it's say 

EBAY otp 5102618554 what is that !? 

[tobiasd4]

Feedback shows you bought 2 items in last month.

[papso22]

OTP usually means One Time Payment, but I am not familiar with it in an ebay context.