[mothered]

All the companies which I found (where i could SE them via little heavy objects) they have a long ToS with a lot of points and cases. This makes me think that they are well protected from being SEd?

Not at all. "Every company" can be SEd.

It's just a matter of Identifying loopholes/vulnerabilities In their terms, and use It to your advantage.

Does the size of the company impact of the success rate of the SE?

No. In fact, the bigger, the better.

Companies on a very large scale are Inundated with orders & claims, hence do not have the manpower to "thoroughly" check each and every claim. The timing of the SE, Is also very Important. For Instance, hitting them during the busiest time of year (Black Friday Deals, Easter or Christmas), adds to their workload and Incapacity to deal with every claim accordingly, thus significantly Increases the chance of a successful outcome.

Once i did a refund on Amazon I will have to wait for a bit long before perform another SE again.

Do remember that every company Is under the Impression that the SE Is a legit claim. Treat It as such, and you won't have a problem.

If you "legitimately" claimed for a refund (with supported documentation) twice In as many weeks, would you experience any Issues? Not at all. The same applies to your SE If It's based on similar grounds.