Credit One Bank false line 0f credit. Las Nevada

I received a credi t card from Credit One Bank stating that my line of credit was for $2,000. But when I received the oreginal card , the amount was for $300.00 . They honnor me with $300.00 and $75 cash back only way I could have gotten cash back is with a pin number which they told me that theywould  send it  ln mail with in 5 to 10 business  days   which they never send.

What flipped  me out when I just spended $208.00 from the $300.00 and remaining was$92.00 left  for my spending. They use that $92.00 as  a debt for  for their pocket. I haven't had that card  less than a month.