Reverse Phone Lookup 69999

This popped up on my cell phone "Joke 4 credits/mo, get 20 credits/mo, text HELP to 69999, T&C's, flycell.com, Quit? txt STOP, 9.99/mo, other rates may apply," followed by a pin number.  Flycell.com appears to be a place to get ring tones, etc. for a cell phone.  I don't appreciate getting this junk on my cell phone, but I'm not going to text back to STOP.  Would I be charged?  Does it let them know they reached a good number?  According to Google, they target young females/teens.  Well, that ain't me, I'm pushing 70.  Dialing *77 blocks marketing calls, but it also blocks someone trying to use a calling card, like people traveling.  Can turn the block on (*77) and off (*87).  Don't know if it works on cell phones, just landlines.

Request: Reverse Phone Lookup 
69999