If you put someone's number on speed-dial, it means that when you hold a number key (example the number  key on your phone) it automatically dials to that person. She wants you to call her but not by mistake. Just go to -call settings- on your phone and then -speed dial- then delete her number there. But not from your 'Phonebook'. Give her some space.. She told you to stop calling, so stop calling. But she also told you she wanted you to keep her number.. it means she has a plan to call you by herself someday, just wait for her to call you.
It means you have her phone number programed on your phone by just pressing one number. If she says to stop calling then I would just stop calling her for now, did you do something to upset her? If so try sending her a gift (like flowers or something) if you want to make up. Dont worry girls can be confusing sometimes all we need is time.