What is the solution for repeated sin that its perpetrator is unable to abandon, and will his repentance be accepted each time?

If you repent with sincere repentance, fulfilling its conditions, Allah will accept your repentance and erase your sin. For the one who repents from a sin is like one who has no sin. If you return to the sin, only the new sin committed will be written against you, and the erased sin will not return. Return and repent, and do not despair of repentance, for Allah forgives what is sought for forgiveness and repented to. This does not license disobedience; rather, it is proof that Allah forgives whoever repents whenever they sin. Repent whenever you sin, and do not despair of repentance, for your despair of Allah's forgiveness is greater than any sin.