I talked to Director of Retail and Consumer Services at Comreg, Barbara Delaney.
Yourtel appear to still be advertising to the Irish market, despite being convicted on 88 sample charges (out of 880) of ripping off their customers. They were fined just €750 of a maximum fine of €5,000 in each case - a total of €66,000. Their pricing scheme and the fact that they have - or had - 5,000 customers for several years makes it clear that the fine barely put a dent in their revenue.
Premium-rate 0818 numbers are hugely expensive to call - 30 minutes on hold for an operator could cost you €15. They are advertised as a way to “earn money from your calls” by phone commercial companies, but their numbering does not follow the 15x pattern of other premium rate lines, and companies are not required by Comreg to publish the price of calling with the number.
These numbers are used by companies such as Ryanair and Sky to make it difficult and expensive to complain about poor service. This practice is explicitly outlawed by the European Directive 2011/83/EU on consumer rights which says
Member States shall ensure that where the trader operates a telephone line for the purpose of contacting him by telephone in relation to the contract concluded, the consumer, when contacting the trader is not bound to pay more than the basic rate.
In guidance for enforcement, they make it clear

To comply with this 'basic rate' requirement, traders should use telephone numbers such as standard (geographic) fixed or mobile numbers that are not subject to any special tariff
regime.
Non-geographic numbers that electronic communications service providers normally include in their offers of 'bundles' of minutes at a fixed monthly price, and numbers charged at no more than rates for calls to geographic numbers would also be examples of numbers charged at the basic rate.
By contrast, traders should, in particular, avoid using those telephone numbers that enable them to finance or contribute to the costs of call centres or draw additional revenues from these telephone calls through revenue sharing with telecom operators, such as Premium Rate Service (PRS) numbers.

Despite this, Comreg have declined to implement this directive into their regulations.