Calls from number similar to mine

[Tlk]

This morning I had a call from a number nearly identical to mine, I missed it so rang it straight back, the lady said she hadn’t rang me and her phone had been on charge. Thought nothing of it, then an hour later I’ve had another call, this time a different number but again only 2 digits at the end different to mine and same story that they haven’t rang me.
Can someone please help with what’s going on? Is it some kind of scam/hack into my phone?

[MI5 · Accepted solution]

@Tlk 

It's just scammers trying it on.

They spoof phone numbers to hide their identity. 

Number spoofing scams - Ofcom

[PJ666]

 A few weeks ago, I received a call from a very similar number to mine - just a couple end digits off. Since then I have been receiving about 5 per week.