Well, assuming that a different phone doesn't have these issues in the house sockets, you have one of two problems.
Either something in your home is interfering with the phones, maybe a florescent light etc.
All three phones have gone faulty.
You could try asking a friend to try one of the handsets at their house. That way you will know for sure.
If it turns out that it is the phones, you should contact V tech and claim for replacements under the warranty, as they are less than a year old.
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