Monaco roaming charge of €4990 per gigabyte

[NFH]

Monaco is covered by the four French networks as well as by one Monaco network. Before going to Monaco, I checked Three's roaming charges for my line and saw that Three would charge me for roaming in Monaco at the same €1.90/GB (0.19c/MB) as for roaming in the EU/EEA, even though Monaco is not in the EU/EEA.

When my girlfriend and I arrived in Monaco, our iPhones initially remained on French networks. After my iPhone automatically switched to Monaco Telecom, I received an SMS from Three at 11:23 confirming that the charge was 0.19/MB (€1.90/GB) for roaming in Monaco, as expected. My girlfriend's iPhone switched to Monaco Telecom at 11:41 according to usage data, but she didn't receive an SMS from Three until 12:07, which retrospectively informed her that the charge would be €4.99/MB (€4990/GB), by which time all €5.81 of her remaining credit had been consumed in just a few seconds.

I have three questions:

1. It is implausible that Three pays a different a wholesale roaming charge to Monaco Telecom for usage by one Three customer compared to another. Therefore why is Three's retail roaming charge 2626 times more expensive for one Three customer than for another Three customer?
2. How can Three justify a charge of €4990 per gigabyte for roaming on a conventional terrestrial (non-satellite) network?
3. Why was there a 26-minute delay in my girlfriend receiving the roaming price SMS notification after connecting to Monaco Telecom, by which time all her credit had already vanished at €4990 per gigabyte? Shouldn't the price notification be sent before any consumption has taken place, especially if the price is so high that even the tiniest amount of usage will generate a significant charge?

[Three_Niall]

Hey @NFH, thanks for contacting us here, if your girlfriend is looking to make a query about her account and charges I would recommend that she contacts customer care directly who can check her account to provide her with more details about her query.

Allowances and charges can vary from plan to plan however as Monaco is not part of the EU this would not be included in an EU Data Roaming allowance. I'd be happy to check your plan for you, Pop through to me here on PM along with your full name, mobile number, address and date of birth and I can check your account for you. 

[NFH]

Thanks @Three_Niall. I realise that question 3 is probably account-specific, but please could you answer questions 1 and 2? As I wrote above, I am aware that Monaco is not in the EU or EEA, but this doesn't explain the price of €4990/GB for one customer while another customer is charged the EU/EEA price of €1.90/GB while roaming on the same Monaco network.

There's no problem on my account, as I was quoted and charged a very reasonable €1.90/GB, so there's no need for me to PM you my account details.

[Three_Niall]

Hey @NFH , unfortunately I wouldn't be able to discuss how the individual plans would be priced with you here as it would depend on the price plan that she agreed to and the cost of out of bundle services when she signed up for the plan. As previously advised if she is looking to to discuss or query the charges on her plan I would recommend that she contacts customer care directly.