Get a high speed connection without roaming charges instantly

I saw this message on an advert:

Get a high speed connection without roaming charges instantly.

I am pretty sure that a better way to say it is:

Instantly get a high speed connection without roaming charges.

If I am right about the first construction being wrong/poor, is there a name for the abusage? I run across such constructions fairly regularly.

Both versions are grammatically correct. Your version (with the adverb at the front) would probably be more common in most writing or speech — it is slightly unusual for an adverb to get separated from its verb phrase by another adverbial phrase like this. In this case it seems OK (at least to my ear); but I’d agree that in some cases the separated version can really be quite horrible, to the point of being ungrammatical; compare:

Sally ate the cake quickly with great pleasure.

?Sally ate the cake with great pleasure quickly.

However, in advertising (like in headline-writing), writers are trying to fulfil a lot of other demands in a very small space, so somewhat unusual phrasings often occur. In this case, putting “Get a high-speed roaming connection” first makes the subject of the ad more immediately clear, and putting “instantly” last gives the phrase a good punchy ending. I’d guess these are the sorts of things the writer had in mind.

I don't think the "instantly" applies to how fast you can get a high speed connection.

It would rather apply to how fast you start having increasing charges as soon as you get said high speed connection.
In that sense, the construction is adequate.