بسم الله الرحمن الرحيم
After you turned mature, whatsoever money and goods you stole of others without their permission it is necessary on you to return them.
(2) Yes, you should return it.
(3) You should give them by any means whether in the form of gift or by transferring into their account or by recharging their mobile, and by doing so you shall be free from this burden.
Allah knows Best!
Darul Uloom Deoband