Won't stay connected to the internet

My wife an I got 2 rca 10 Viking pro from Wal-Mart. Got home hooked up took for ever. Now both tablet are not staying connected to the internet they both pops off an on all the time. An can't do anything with them an I want to use it for work but can't if it won't stay connected even an my job the tablet does the same thing one min on next off then repeat. So what can we do to fix or just take them back an get money back