when i create a service for $50 paypal,if give any how order on this gig,if the buyer cancel this order by admin after i done the work,so what can i do at this moment??

when i create a service for $50 paypal,if give any how order on this gig,if the buyer cancel this order by admin after i done the work,so what can i do at this moment??

when i give a gig like as it(i will give u $50 paypal for $70)if that time buyer canceled this order by admin after i done this work so what can i do at the time..is there any risks.