Have 0844 Call Charges changed

[#1]

The Misses is fond of calling her parents in a far away land using an access number of type 0844. Up until recently it was proving very economical, however recently I was alerted that my home phone credit limit had been breached. £75 !!! It appears that the access number that was supposidely charging me 1p/min was actually costing me12p/min.
So I quickly put a stop to this very convenient but expensive access number and am looking at my alternatives.
My question is who is to blame for this sudden change of pricing, Ratebuster.co.uk maintain on their website that the cost of a call to India is still 1p/min.

[#2]

it's part of the uk calling changes - see https://www.plus.net/ukcalling/ so basically all telecoms providers are adding 10p a minute..

[#3]

Call costs to 0844/0845 numbers changed on 1st July 2015 under new OFCOM rules.
And Plusnet (and all the telecom companies) used it to maximise profits.

Now Plusnet charge an "ACCESS FEE" of  9.58p per minute, see https://www.plus.net/ukcalling/ and the ratebuster add on their charges on top.

[#4]

18185 and similar are still 'free' on the Plusnet part of the call (you just pay the service operator's fee) as far as I'm aware.
The other good option is to use VOIP e.g. https://www.freevoipdeal.com/
*Other 'free' access numbers and VOIP providers are available.