Finally hired a lawyer to get oil royalties -- interest question

After 8 months of continental refusing to send us anything pertaining to royalties I had to hire a lawyer to write a letter to try and get my families royalties… its been over a year since the wells have been pumping oil.

In the letter my lawyer is asking for interest, my question is how likely am I to get said interest, and will this finally light a fire under them to pay my family what they owe me?