Welcome to ELU. Your reason for looking for this word or phrase is very clear. As a matter of a fact, it is one of those rare cases where (as far as I can discover) there is no word or phrase for quite a common situation. But it is such a common situation (type of of behaviour), that I am surprised to find that my searches give me nothing.
'to use a sledgehammer to crack a nut'
This is about the use of an excessively elaborate, large or expensive implement or method to solve a very small or minor problem. That is not quite what you want. The sledgehammer will work, even though it shatters the nut into an uneatable mess of shell and nut.
I found one word that might do, following the old proverb
The greeks had a word for it.
There is a word καταχρησθαι (catachresthai), which is from the preposition cata (κάτα), meaning 'down', often in a negative sense, an chresthai (χρησθαι), to use. I can mean to use up or to misuse. It did eventually come to have the additional sense of the misuse of words.
Does it come into modern English? That is the problem. It does, but with the very specific meaning of the misuse of words. I find the following entry in Oxford dictionaries:
The use of a word in an incorrect way, for example the use of mitigate for militate.
Mid 16th century: from Latin, from Greek katakhrēsis, from katakhrēsthai ‘misuse’, from kata- ‘down’ (expressing the sense ‘wrongly’) + khrēsthai ‘use’.
That is as near as I can get and I fear it is not near enough. The only way you could get away with coining it would be to become a widely known celebrity and utter it on air or online, so that it catches on, or to make it known within a smaller special group of people in some specialist area (such as engineering).
Otherwise, I see nothing at all wrong with how you yourself expressed the situation!