Incomplete cycle.

Salt tank is 5/8 full of water. I can hear the cycle start at 1:00 am. I noticed that the back flush started taking longer to complete. The second incomplete cycle started 2 days ago. I don't have a manual to correct this. I am a 78 yr. old female at your mercy.
I bought this Amazon water Treatment System 8/13/97 in NM. Have been unable to contact a NM customer service. have not had any problems until recently. I am going to be out of the house for 1.30 hours starting in a few minutes. Hope to hear from you.