not yet received the rest of my federal refund .. over 5000$

Q) I received a letter saying that i hadn’t filed my 2013 and 2015 returns. They put the amounts owed for each year and said not to do anything if i agreed with the amounts they would apply them to my 2018 tax return on may 8th 2019. However its almost July and ive not yet received a adjustments letter or the rest of my federal refund which was over 5000$ after they do the offset.. What am i to do i need this badly as im low income father of 3 alone.?
A) Please contact the IRS regarding your refund. IRS help lines are open Monday through Friday. Residents of Alaska and Hawaii should follow Pacific time. Phone lines in Puerto Rico are open from 8 a.m. to 8 p.m. local time.
Individuals
800-829-1040
7 a.m. to 7 p.m. local time
Businesses
800-829-4933
7 a.m. to 7 p.m. local time
Non-profit taxes
877-829-5500
8 a.m. to 5 p.m. local time
Estate and gift taxes
866-699-4083
8 a.m. to 3:30 p.m. Eastern time
Excise taxes
866-699-4096
8 a.m. to 6 p.m. Eastern time
Overseas callers
Use our International Services page.
Callers who are hearing impaired
TTY/TDD 800-829-4059
Requesting a face-to-face meeting for help
You can make an appointment at an IRS local office to get help. Appointment times vary by tax issues and office locations.
You can find the office closest to you with our Taxpayer Assistance Locator tool. Once you find your local office, call 844-545-5640 to schedule an appointment.