Poor signal

[Thiru]

I changed my o2 contract a month ago for myself and two other family members since then I am having very poor signal, can't even make WhatsApp calls. 

[Enlli]

That does sound bad.

What does https://status.o2.co.uk/ show

Also check 

Guide: How can I sort out my network issues? 

Guide: Is the network down for me or everyone? 

It may be you are in a poor spot or the network is oversubscribed 

Never trust coverage maps they are computer predictions. Always worth checking with PAYG SIM cards on different networks 

[Bambino]

@Thiru O2 only offers a 14 day change your mind period, and as you're now a month into your contracts you're locked in for however long you signed up for. All we can suggest is you try WiFi calling when you're indoors: Wifi and 4G Calling explained | O2 It needs to be enabled on O2's end first before you can use it.