Don't know if it was 0.5% of the customers I have both a globalsimcard.co.uk and travelsimcard..co.uk and both were offline. I must have been unlucky having 2 cards offline.

If you want to argue about what is posted on a website or not. My point is that your competitor did feel the need to inform customers about a problem. Even if it's like you say ony effects a small %, for those it saves them calling you asking what is going on. It saves you telling the same story 100 times.
For me it just shows that this provider actively monitors the system and in case of an error reports this. For me this is an example of good service. And yes there is more than this that makes a good service.

What I do find bad service is the situation where some providers including yourself have talked about the launch of a dual sim card but keep delaying this. Maybe it's time to either take the offer offline or give us some background info why this keeps on delyaing and delaying. Informing your customers even if it's not good news is also part of customer service.

It was 0.5% of our customers.

Who is to say the system / service is not actively monitored 24/7?

With such a small percentage of users affected, many of which were not actively using their SIMs at the time, the need to alert unaffected users was deemed unnecessary.

Different companies have different perspectives and priorities at any given time. Because one company chose to do one thing and another something else, does not mean that one is "better" than another, simply that at that particular time and circumstance, they chose to address different issues, probably because each company was being affected differently at that point in time.

This is not about "bad service", but of keeping relevant customers fully informed, of which any dealer of reputation and good standing certainly will have been via email or on their website as they see fit.

I'm not disputing the amount, probably you don't have other choices. However just looking around I've noticed something that might put things into perspective: you can buy nowadays a Nokia prepaid including a Vodafone (I think) prepaid card for 9.97 EUR. And that includes shipping (amazon.de) if you buy more than 20EUR merchandise (which isn't hard). So a current, new (yes, basic and simlocked) phone with everything (battery, charger, SIM) is much cheaper (retail!!!) than a SIM card (wholesale).

So on one side we have EU-roaming with 0.19EUR incoming/0.43 EUR outgoing EU-wide (including to EU mobiles) even for the lousiest prepaid in EU. On the other side you have huge costs like 67$ shipping or 15-20$ SIM card (before anybody in the chain even starts thinking about a profit and before the customer actually using any service). In the end it's really tough to grow (or even keep) such a business and I respect anybody that even tries.