What is the link to pay Atascosita fees? They have been sending

What is the link to pay Atascosita fees? They have been sending emails to my dead husband and for some reason he hasn't called them back.......haha actually why did they not send me the email since I paid a month ago but maybe more now. Let me tell you, it is difficurt to know but the cell phone keeps me in crap I have to pay. I am so glad I planed ahead for this but I thought I might have be done for this since I paid what they told me a few months but now I can't find them.